Effect of Metal Coating on FRP Blade Lightning Failure for Wind Power Generators

Abstract

In Japan, with the recent increase in wind power generator installations, the incidence of lightning damage to FRP blades is increasing. Lightning damage is a significant issue in Japan since lightning in Japan seems severer than that in Europe or the US. In Kochi, Japan, six 600-750 kW grade generators have been installed, and some have been damaged by lightning several times. To resolve this problem, the Kochi University of Technology received a request in 2002 from the Kochi prefectural government for research into lightning protection. After surveying the literature and questioning related organizations such as NREL and Toray USA, experiments to protect against lightning damage to FRP blades of wind power generators were planned. Half size models and two 1/4 parts of a full size 250kW blade were prepared as specimens for this research. The method investigated to protect against lightning damage was metal coating. The aim being to protect against blade failure by using metal coating in actual field situations; by using a 1/2 size model and the full size blade specimens in an experimental situation. As in previous experiments, these ones were mainly conducted in the Toshiba Hamakawasaki High Voltage High Power Testing Laboratory. This Testing Laboratory is one of the biggest test laboratories for experiments involving high voltages and large currents.